How do we know that faith unaccompanied by works is valid in the Reformed tradition?

From a Reformed perspective, faith is understood as a gift from God that results in a transformation of the believer's life, leading them to act in accordance with God's will. Though we emphasize that we are justified by faith alone (sola fide) and not by works, this faith inevitably manifests itself in good works as a response to God's grace. Therefore, while works do not save us, they are a necessary evidence of a living faith. As James 2:17 illustrates, faith without works is dead, affirming that the true believer will demonstrate their faith through their actions as a result of being transformed by Christ.